环己烷溶液中聚丁二烯基双锂引发剂的制备

Synthesis of a polybutadienyl dilithium initiator in cyclohexane solution

在环己烷溶液中,由萘锂和丁二烯反应制备了聚丁二烯基双锂引发剂。利用阴离子活性聚合特点和溶度参数相近相溶原则,采取有条件分批加料的方法,解决了萘锂在环己烷溶液中不溶、引发效率低的难题。结果表明,在丁二烯的环己烷溶液由1次加入改为2次加入、溶液摩尔浓度c丁二烯≥0.75c萘锂、丁二烯聚合度达到2之前体系中环己烷溶液加入量V丁油≤1.33V萘锂的条件下,可实现聚丁二烯基双锂引发剂制备反应在均相体系中进行;引发聚合实验证明,所制备引发剂活性没有变化。

A polybutadienyl dilithium initiator has been synthesized from butadiene and lithium naphthalenide in cyclohexane solution by an electron transfer-coupling reaction.In order to resolve the problem of the insolubility of lithium naphthalenide and its low initiation efficiency in cyclohexane solution,a new method has been proposed based on the controllability of anion polymerization and the solubility parameter principle.It was found that the conversion of lithium naphthalenide could be conducted in a homogeneous phase under the following conditions：（i） the butadiene-cyclohexane solution was added in batches;（ii） the concentration of butadiene-cyclohexane solution was greater than 75% of the concentration of lithium naphthalenide;（iii） the volume of butadiene-cyclohexane solution added was less than 1.33 times that of lithium naphthalenide solution before the degree of polymerization of butadiene reached 2.Solution-polymerized styrene-butadiene rubber（SSBR） was synthesized using the resulting polybutadienyl dilithium initiator in 5L and 200L agitated reactors,showing that the initiator is suitable for use in industrial production.